Figure 3
From: Non-empirical identification of trigger sites in heterogeneous processes using persistent homology
Examples of phase maps (bottom image in each panel) and the corresponding persistence diagrams (upper image in each panel) for (a–c) calcium ferrites and (d–f) iron oxides during the (a,d) early (S-1), (b,e) intermediate (S-2), and (c,f) final (S-3) stages of reduction. The blue circles show the centres of the representative shapes in each image (calculated using a PCA analysis) that became predominant as the reduction progressed.
